Smoke-preventing furnace



(No Model.) 5' sheets-sheet 1.

A. BALDWIN. SMOKE. PREVENTING FURNAGE. No. 518,576. Patented Apr. 17,1894.

(NpMoael.) 5 sheets-sheet 2.

. J. A. BALDWIN.

SMOKE PREVENTING FURNAGE.

No. 518,576. 'atented Apr. 17, 1894.

E NATIONAL uwoqmumma coMPAnY.-

WASHINGTON. D. c..

(No Model.) 5 sheets-sheet s. J. A. BALDWIN. SMUKB PREVENTING PURNAGB.No. 518,576.' Patented Apr. 17, 1894.

(No Model.) 5 Sheets-Sheet 4.

'J. A. BALDWIN. SMOKE PREVENTING FURNAGB.

No. 518,576. Patented Apr. 17, 1894.

5 Sheets-Sheet 5. J. A. BALDWIN. SMOKE PREVENTING PURNAUB.

Patented Apr. 17, 1894.'

(No Model.)

\.N im EN i mmlmnmmm Hur E DE H DDDU H DDDUUELUEQ |l l \w\ o o o m Q M MM OOOOOOOOO-OOOOOOOO |v\ M o o M Mw Nrrn *rares ATENT Ormes..

JUDSON A` BALDVIN, OF BENTON HARBOR, MICHIGAN, ASSIGNOR TO GEORGE W.HALE, OF CHICAGO, ILLINOIS.

SMOKE-i-PREVENTING FURNACE.

SPECIFICATION forming part of Letters Patent No. 518,576, dated April17,1894.

Application filed March 18,1892. Serial No. 425,377. (No model.)

To @ZZ whom it may concern:

Be it known that I, JUDSON A. BALDWIN, a citizen of the United States,residing at Benton Harbor, in the county of Berrien and State ofMichigan, have invented certain new and usefullmprovements inSmoke-Consuming Furnaces, of which the followingis a full, clear, andexact description, reference being had to the accompanying drawings,forming `a part of this specification.

My invention relates to furnaces for steamgenerators, either such as areused for supplying steam to engines, or to heating-systems or for any ofthe purposes to which steamgenerators are or may be applied, and myinvention relates also to furnaces for steam generators and for variousother similar and analogous heating purposes.

Among the primary objects of my invention is included that of producinga furnace which shall completely, thoroughly and rapidly consumeabsolutely all of the infiammable products of combustion, both solid andgaseous, such as usually escape from furnaces in the form of smoke, andwhich shall possess a free draft and be under perfect control at alltimes. Furthermore, to produce a furnace in which the products ofcombustion shall be first directed downward through an upper grate andthen over a lower grate, so as to effect not only an absoluteconsumption of all of the inflammable products of combustion, but also amost thorough and economical consumption of the fuel itself.

A still further primary object of my invention is to produce a furnacein which the fuel shall be disposed at greater depth at points where thedraft or combustion is the more vigorous, and at less depth at pointswhere the draft or combustion is less vigorous, and thus insure aperfectly uniform rate of combustion throughout the furnace, and a mostthorough and complete consumption of the fuel.

The primary objects of my invention also include that of producing afurnace, of the kind in which water-'grates are used, which shallpossess a free water-circulation and also a maximum rate of effectiveheat-application to the water, so as to insure both a perfect andgeneral heating action upon the water at an economical rate offuel-consumption.

Furthermore, another primary object of my invention is to produce afurnace in which both the upper and lower grates shall be subj ectedonly to the action of a downward draft, `and in which the air suppliedto the grates shall be composed partly of air heated previous to itsentrance into the furnace, and also partly of cold air taken directlyfromthe external atmosphere, whereby a most vigor ous combustion shallbe insured, and whereby also the furnaceroom shall be maintained at acomparatively low temperature.

To the above purposes, my invention consists in cert-ain peculiar andnovel features of construction aud arrangement, as hereinafter describedand claimed. y

The more precise nature of my invention Willbe better understood whendescribed with reference to the accompanying drawings, in which- Figure1 is a vertical longitudinal section of a smoke-consuming furnaceembodying my invention the furnace beingshown as applied to acylindrical boiler. Fig. 2 is a view of the same, partly infrontelevation and partly in transverse vertical section. Fig. 3 is avertical longitudinal section of afurnace embodying my invention appliedto a safetyboiler. Figli is a view of the structure shown in Fig. 3;this view being partly in frontend elevation and partly in transversevertical section. Fig. 5 is a vertical longitudinal section of a furnaceembodying my invention and applied to a cylindrical boiler; the furnacehaving but a single bridge-wall.

The furnace embodying my invention is i adapted for use in connectionwith boilers or generators of a great variety of structural types, andfor this reason I have shown it in Figs. 1, 2, and 5 as applied to acylindrical boiler or generator 2, of the usual or any preferred kind;this boiler 2 being shown as placed horizontally in a suitable settingof `brick or masonry work, and the furnace shown in Fig. 5 differingfrom thatshown in Figs. 1 and 2 principally in having a singlebridge-wall 16 in lieu of such wall and an auxiliary bridge-wall 15, asshown in Figs. l and 2.

In Figs. 3 and 4, I have shown the furnace IOO as applied to a safetyboiler or generator, of

what is known as the Harrison-Wharton type of construction, and whichconsists typically of sections or slabs each composed of a plurality ofglobular chambers or units having internal communication with eachother. I wish it to be distinctly understood that 1 donot propose toconfine myself exclusively either to these precise applications of thefurnace, or to the application of the furnace to steam-generators, as itis capable of various other uses within the spirit of my invention.

The furnaces shown are of the type known as water-grate furnaces and thearrangement of circulating and grate pipes and of the drums is shown assimilar to those shown and described in LettersPatent No. 470,171,granted to myself March 8, 1892, and I also desire it to be understoodthat I do not propose to conne myself exclusively to this precisearrangement of water-circulating connections. Indeedcertain features ofmy invention are equally applicable to furnaces having other thanwater-grates; such being true as to the inclined relation of thesections of vthe upper grate, in association with a lower grate which isalso solely a downdraft grate, as will be evident from the ensuingdescription.

Referring first to the structure shown in Figs. 1 and 2, 3 designatestwo pipes which are connectedat their upper or rear ends to the underside of the shell 2, at opposite points from the median line of saidshell, and 4 designates two pipes the upper ends of which are connectedto the shell 2 at opposite sides l thereof, and at a considerably higherlevel 'per grate.

than that of the points of connection of the pipes 3, the intentionbeing to take the water lfrom the boiler at lower or cooler points, bymeans of the pipes 3, and after passing it through the furnace so as toheat it, to return it to the boiler, by the pipes 4, at higher or warmerpoints. The pipes 3 are shown as extending forward beneaththe shell 2and as` connected at their lower or forward ends to a drum 5 whichextends horizontally beneath and transversely ofthe shell, and also justback of the tp of the main bridge-wall 16. From this drum 5 lead pipes 6which extend vertically downward behind the mainbridgeber, andtransversely of said chamber, and to said drum are connected the frontends of the upper pipes 9 and lower pipes 10 of the up- The peculiarrelative positions of these pipes 9 and 10 will be hereinafter fullydescribed, but for the present it will suffice to state that the rearends of said pipes are connected to a third drum 8 which rests upon thetop of an auxiliary bridge-wall 15, and that the lower ends of the pipes4 are connected to said drum 8, so as to take the water therefrom. Themain bridge-wall 16 terminates at its top below the under side of theshell 2, so as to leave a space for the escape of the noncombustibleproducts, and across theA lower part of the main bridge-wall extends ahorizontal air-channel 18 the ends of which open out of the side wallsof the setting orfurnacechamber. An air-passage 17, or if desired aplurality of such air-passages, leads upward from the Achannel 18 andopens at the front of the top of the main bridge-wall, and asteam-supply pipe 23 leads across the upper part of the mainbridge-wall, below the upper end of the channel or channels 17, and isprovided with a number of discharge-nozzles 24 which deliver steamforwardly and upwardly to and through the upper ends of the channels 17.This arrangement of air-channels is such that the air is drawn into thepassage 18, through the ends thereof, and fiows upward through thepassages 17, and is discharged at the upper ends of said passages; thesteam-jets issuing from the discharge-nozzles 24 serving to insure afree iiow of air through the air-channels, and such air being heated bythe hot vbridge-wall 16. A second transverse air-passage 182"L is shownas formed in the bridge-wall 16, at a point above and in front of thechannel 18'; this channel 18a opening at its ends through the sides ofthe furnace-chamber, and communicating with air-chan nels 18b leadinghorizontally forward in the side walls of the furnace-chamber, andcommunicating attheir front ends with airinlet openings 12 which arealso formed in the side-walls of the furnace-chamber. The air alsoenters the channel 18Eb through the ends thereof, and flows through saidchannel and the channels 18h, and enters the furnacechamber through theopenings 12; the air being heated bythe hot bridge-wall 16 and by thehot side-walls of the furnace-chamber. The auxiliary bridge-wall 15rests upon the front of the main bridge-wall 16 and is inclined upwardlyand forwardly therefrom so as to leave a space between itself and themain bridge-wall for the passage of the unconsumed products ofcombustion. This auxiliary bridge-wall is formed with numerous openingsextending from its front surface to its rear surface; the unconsumcdproducts of combustion being compelled to pass through such openings,and being consequently thoroughly broken up and highly heated, and theopenings or channels in the auxiliary bridgewall being of sufcientlength to insure an effective retorting action upon the products ofcombustion passing therethrough. The space between the two pipes 4 isclosed by a wall 14 of fire-brick, or other refractory material, whichalso extends from the top of the auxiliary bridge-wall to the under sideof the boiler-shell 2. The outer ends of the airchannels 18 and 18a arepreferably covered by damper-plates 18, and two fire-doors 19 and 20 areprovided in the front wall of the furnace-chamber; an ash-pit door 21being also provided below the lower fire-door 20.

, The furnace shown in Fig. 5 differs from the furnace shown in Figs. 1and 2 principally in having no auxiliary bridge-wall 15 the drum 8being, in this instance, supported upon a girder 29 which extends fromone sidewall of the furnace-chamber to the other. In all other respects,the construction and arrangement are similar to that previouslydescribed,and like parts are designated by like numerals of reference insaid Figs. 1, 2 and 5.

In Figs. 3 and 5, 27 designates a portion of a safety boiler, of what isknown as the Harrison-Wharton type, and the principal differences inconstruction between this structure and those shown in Figs. 1, 2, and5, relate to the drum 5, the bridge-wall 15, and to the connectionsbetween the drum 8 andthe front part of the generator. In thisinstancethe rear or upper ends of the pipes 6 are connected to a drum 5 which isdirectly connected to alowerpart of the generator, at the rear thereof,and a second drum 25 is directly connected to the front part of thegenerator, at a point above the level of the point of connection of thedrum 5. Pipes 26 connect the drum 25 with the drum 8, said pipesextending obliquely upward and forward at the top of thefurnace-chamber, and a wall 28 of fire-brick, or other refractorymaterial fills the space between the top of the furnace.

chamber and the under side of the generator 27. The auxiliarybridge-wall extends vertically upward,in thisinstance, from the lowerpart of the main bridge-wall 16, and the space for the passage of theproducts of combustion is inclosed between the front surface of the mainbridge-wall 16 and the rear surface of the auxiliary bridge-wall 15 andof thelining or partition 28. In all other respects, this structure issimilar to that shown in Figs. 1 and 2, and also to that shown in Fig.5, and like parts are designated by like numerals of reference in all ofsaid figures.

In all of the three forms of the furnace above described the two drums 7and 8 are connected together by the upper bars 9 and the lower bars 10of an upper furnacegrate, and the upper and lower bars of this upperfurnace-grate are inclined relatively t0 each other in such manner thatthe space between said upper and lower bars is deeper at points nearerthe draft-entrance and"`shallower at points more remote from said draftentrance. As shown, this result is accomplished by imparting a greaterforward and downward inclination to the lower grate-bars 10 than to theupper grate-bars 9; the front ends of the lower gratebars being bentupward so as to properly connect with the drum 7. However it is to bedistinctly understood that the diminution in the depth ofthe spacebetween the upper and lower grate-bars may be accomplished either byimparting the excess of inclination to the lower grate-bars as shown, orto the upper grate-bars; the higher ends of the upper grate-bars being,in this latter instance, a greater distance above the lower grate-barsthan would be the lower ends of said upper grate-bars. Nor need theinclination, in either event, be from rear to front as shown, nor,furthermore, need the grate-bars necessarily be water-bars since thisfeature of my invention is equally applicable to other thanwater-grates.' The front end of the upper grate is shown as below thefire-door opening 19, and the upper grate-bars 9 are also shown as belowthe inlet-openings 12 for hot air at the sides of the furnace. Cold airinlets 13, in the form of inwardly and downwardly extending pipes, arealso shown as placed in the front wall of the furnace-chamber above theupper grate, so that the draft to said upper grate is wholly andconstantly a downward draft; the fire-door 19 being always kept closedexcepting at the actual moments of introducing fuel to the grate. Thebars of the upper grate 9 are preferably arranged in line with thespaces between the bars of the lower grate 10, and if desired, thespaces between the lower grate-bars may be narrower than the spacesbetween the upper grate-bars.

The intention is to feed the fuel directly upon the upper grate-bars 9,and as the fuel burns it will fall upon the lower grate-bars 10, eitherpartly-or wholly filling the space between the upper and lowergrate-bars. The products of combustion areforced downward through themass of fuel upon the upper gratebars and also through the mass of fuelupon the lower grate-bars, and a very thorough combustion of suchproducts is thus attained. This result is further insured by theadmixture of hot and cold air afforded by the air-inlets 12 and 13, andthe latter also keep the boilerroom comparatively cool inasmuch as theyrapidly draw air directly from such room. From the lower grate-bars 10,the products of combustion flow backward through the space between thelower grate 10 and the blind grate 11. Thisblind-grate 11 consistssimply of a number of plates set closely together, side by side, uponthe water-pipes 6, and said plates serve to catch and hold the hot ashesand small incandescent coals which drop from the lower grate 10, as theresult of ordinary combustion, or of raking said lower grate 10. Thereis no updraft whatever through the blind grate 11, the ash-pit door 2 lbeing always kept closed excepting at actual moments of removing ashesfrom the pit. The mass of .hot ashes and coal upon the blind grate 11`serves to heat the escaping gaseous products of combustion, which thenare consumed within the openings in the auxiliary bridgewall 15, orwhich in any event when mingled y with the steam and hot air from thechannels 17 instantly burst int-o a mass of flame and are totallyconsumed fas they'tiow over the top of the main bridge-wall 16. Theplates composing the blind gra-te will, of course, be form-ed withopenings or holes large enough to permit the ashes to -beraked downthrough 1l also radiating their heat downward upon the supporting pip-es6,*so as to heat the waterV owing through the latter. ,n

Having thus described my invention, what I claimas new therein,anddesire to secu re by Letters Patent, is-

its draft wholly downward from such upper grate, substantially as setforth.

2. A downdraft-f.urnace,comprising an u-pper downdraft-grate composed ofa plurality of sets of upperand lower water-grate bars so disposedrelatively to each other as to prol duce an intervening space of greaterdepth adjacent to adraft-inlet and of less depth rel mote from such.draft-inlet, and a blind-grate located below the Vlupper grate andsupported upon water-heating pipes, and 4also receiving its draftwhollywdownward fro-m the upper grate, substanti-a-lly'as set forth.

3. A doWndraft-furnace,coinprising an upper and also -a lower grate eachvcomposed of a plurality of sets ot' grate-bars so disposed relativelyto each other as to produce an intervening space of greater and lessdepth, hot-air inlets located above said upper grate and in the sidesofthe turnacachamber, and otherI air-inlets located inthe front of 'thefurnace-chamber and also above said upper grate, substantially as setforth.

4. A downdraft furnace, comprising a tirechamber containing abridge-wall provided with air-heating inlet-passages, a plurality ofwater-heating drums located at the front and rear of said chamber, anupper downdraft :gratecomposed of a set of upper tubular grate-barsconnected Ito said drums, vand a vlowersetot tubular grate-bars alsoyconnected 'the upper grate-bars as to produce an Vintervening space ofgreater depth adjacent to a draft-inlet and of less depth remotefromsuch `draft-inlet, and a blind downdraft grate lol lcated below theupper grate and receiving its- 1. A downdraft-furnace, comprising anupper downdratt grate composed of upper gratebars and a lower set ofgrate-bars so disposed relatively to the upper bars as to produce an fintervening space of vgreater depth adjacent to a draft-inlet and Aofless depth remote from such draft-inlet, and a blind down-draft gratelocated below the upper grate and receiving f rdraft'wholly downwardfrom said upper grate, substantially as set forth.

A dow-ndraft furnace, comprising a tirelchamber containing a bridge-wallhaving air- `heatinginlet-passages, a pair of dru-ms one of which islocated in the fron-t and the other in the rear of the chamber, avplurality yof pipes connecting the rear drum to a boiler andsupporti-ng a closed wall or lining, an upper downdraft grate composedoi' an upper set of tubular bars connected to said drums,and la lowerset of tubular bars also -connected to the drums, and a blind'downdra'ft grate located below the upper grate and receiving its draftwholly downward from said upper grate, substantially as set forth.

J UDSON A. BALDWIN.

Witnesses: l

IRWIN VEEDER, Tom) MASON.

